JP7508981B2 - Elastic Crawler - Google Patents

Description

The present invention relates to an elastic crawler. In particular, the present invention relates to an elastic crawler that is attached to the traveling device of agricultural machinery, construction machinery, etc.

Crawler-type travelling devices, such as agricultural machines such as combine harvesters and tractors, and construction machines such as backhoes, are equipped with elastic crawlers in the form of endless belts. An example of an elastic crawler is disclosed in the following Patent Document 1.

Figure 5 shows a cross section of a conventional elastic crawler 2. The elastic crawler 2 includes a crawler body 4, a guide protrusion 6 protruding inward from the crawler body 4, and a lug 8 protruding outward from the crawler body 4.

In the traveling device, the guide protrusion 6 meshes with the sprocket. The sprocket rotates and moves the guide protrusion 6. The elastic crawler 2 moves in the circumferential direction, and the traveling device travels. From the viewpoint of transmitting driving force, the guide protrusion 6 is configured to have high rigidity.

To ensure rigidity, the guide projection 6 includes a metal core body 10. A tension member 12 is located on the outside of this core body 10. The core body 10 and tension member 12 are usually covered with an elastic member 14 such as cross-linked rubber. As shown in FIG. 5, the outer surface 16 of the guide projection 6 has a shape that generally follows the shape of the core body 10. In this elastic crawler 2, the shape of the core body 10 is reflected in the entire outer surface 16 of the guide projection 6.

JP 2005-271711 A

If the guide protrusions are made only of elastic material, a light elastic crawler is obtained. This elastic crawler improves the fuel efficiency of the traveling device. At the same time, the driving force of traveling devices is increasing. Making the guide protrusions only of elastic material is disadvantageous in terms of rigidity and wear resistance.

When a guide protrusion is made only of an elastic material, there is a risk of it coming off the track if sufficient rigidity and abrasion resistance cannot be ensured. In order to prevent this, it is being considered to configure the guide protrusion with a pair of flanges arranged in parallel in the width direction. In terms of ensuring the rigidity of the guide protrusion, it is difficult to obtain a guide protrusion with a pair of flanges without using a core body. The use of a core body is essential to exert driving force and improve resistance to coming off the track. There is a need to establish technology that can achieve weight reduction while still creating a guide protrusion that includes a core body.

The present invention was made in consideration of these circumstances, and aims to provide an elastic crawler that can reduce weight while ensuring the rigidity and wear resistance of the guide protrusions.

An elastic crawler according to one aspect of the present invention comprises an endless belt-shaped crawler body and a guide protrusion protruding from a roller passing surface formed on the inner peripheral surface of the crawler body. The crawler body includes a tension body extending in the circumferential direction. The guide protrusion includes a core body. The tension body and the core body are covered with an elastic member. The maximum width of the core body is narrower than the maximum width of the guide protrusion. The guide protrusion comprises a pair of outer surfaces located outward in the width direction. A portion of each outer surface includes a first core body reflecting zone having a shape that follows the shape of the core body.

Preferably, in this elastic crawler, the core is exposed in the first core reflection zone.

Preferably, in this elastic crawler, the ratio of the area of the first core reflection zone to the area of the outer surface is 10% or less.

Preferably, in this elastic crawler, the ratio of the height from the roller passing surface to the first core reflection zone to the height of the guide protrusion is 20% or more and less than 50%.

Preferably, in this elastic crawler, the guide protrusion has a groove recessed outward from the top surface. A portion of the groove wall includes a second core body reflection zone having a shape that follows the shape of the core body.

Preferably, in this elastic crawler, the core is exposed in the second core reflection zone.

Preferably, in this elastic crawler, the ratio of the area of the second core reflecting zone to the area of the groove wall is 10% or less.

Preferably, in this elastic crawler, the ratio of the height from the bottom of the groove to the second core reflection zone to the depth of the groove is 60% or more and 90% or less.

Preferably, in this elastic crawler, the bottom of the core body is located outside the wheel passing surface.

Preferably, in this elastic crawler, the crawler body includes a reinforcing layer on the outside of the tension body, and the reinforcing layer extends in the circumferential direction.

Preferably, in this elastic crawler, the position at which the core exhibits its maximum width is located between the top and bottom of the core.

Preferably, in this elastic crawler, the position where the core exhibits its maximum width is included in the first core reflection zone.

Preferably, in this elastic crawler, the core body is made of metal.

The present invention provides an elastic crawler that can reduce weight while ensuring the rigidity and wear resistance of the guide protrusions.

FIG. 1 is a side view showing an example of a traveling device equipped with elastic crawlers according to an embodiment of the present invention. FIG. 2 is a side view showing a part of the elastic crawler. FIG. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a cross-sectional view showing a portion of a conventional elastic crawler.

The present invention will now be described in detail based on a preferred embodiment, with reference to the drawings as appropriate.

[Running gear]
1 shows an example of a crawler type traveling device 22. The traveling device 22 includes a sprocket 24, an idler 26, a roller 28, and an elastic crawler 30.

The sprocket 24 is located on the front side of the running gear 22. The sprocket 24 is disk-shaped. The sprocket 24 has a large number of teeth 32 on its outer periphery. The sprocket 24 is rotatably supported by the machine body 34. Although not shown, the machine body 34 has a built-in driving means such as a prime mover. The driving means rotates the sprocket 24.

The idler 26 is located on the rear side of the traveling device 22. The idler 26 is disk-shaped. The idler 26 is rotatably supported on the machine body 34.

The rollers 28 are located between the sprocket 24 and the idler 26. The rollers 28 are rotatably supported by the machine body 34. On the running gear 22, multiple rollers 28 are arranged at intervals.

The elastic crawler 30 is an endless belt. The elastic crawler 30 is wrapped around the sprocket 24, the idler 26, and the roller 28.

Although not described in detail, in this traveling device 22, when the sprocket 24 rotates, the elastic crawler 30 moves in the circumferential direction and the idler 26 rotates. This causes the traveling device 22 to travel. The rollers 28 roll on the elastic crawler 30 on the road surface side.

[Elastic crawler 30]
FIG. 2 shows a part of the elastic crawler 30 shown in FIG. 1. In FIG. 2, the left-right direction is the circumferential direction of the elastic crawler 30. The circumferential direction of the elastic crawler 30 is also the length direction of the elastic crawler 30. In FIG. 2, the up-down direction is the thickness direction of the elastic crawler 30. As shown in FIG. 1, the elastic crawler 30 forms a loop. In FIG. 2, the upper side is the inside of the loop (hereinafter also referred to as the inside), and the lower side is the outside of the loop (hereinafter also referred to as the outside). The direction perpendicular to the paper surface is the width direction of the elastic crawler 30. The left side of the paper surface is the front side of the traveling device 22, and the right side is the rear side of the traveling device. When the traveling device moves forward, the elastic crawler 30 shown in FIG. 2 moves from left to right.

Figure 3 shows a cross section of the elastic crawler 30 taken along line III-III in Figure 2. Figure 3 shows a cross section of the elastic crawler 30 taken along a plane perpendicular to the circumferential direction of the elastic crawler 30. In Figure 3, the left-right direction is the width direction of the elastic crawler 30. The upper side is the inside of the loop, and the lower side is the outside of the loop. The direction perpendicular to the paper surface is the circumferential direction of the elastic crawler 30. The dashed-dotted line CL is the center line in the width direction of the elastic crawler 30. Line III-III in Figure 2 is the circumferential center line of the core body, which will be described later.

The elastic crawler 30 comprises the following components: an elastic member 38, a core body 40, a tension body 42, and a reinforcing layer 44.

The elastic member 38 is made of cross-linked rubber. Although not described in detail, in the elastic crawler 30, the elastic member 38 is made of a rubber composition for cross-linked rubber that is generally used as the cross-linked rubber of the elastic member 38. The elastic member 38 covers the core body 40, the tension member 42, and the reinforcing layer 44. The outer surface of the elastic crawler 30 is almost entirely made of the elastic member 38.

The core body 40 is made of metal. Examples of the material of the core body 40 include ordinary steel and alloy steel. The core body 40 may be made of resin. In this case, a thermoplastic resin having a melting point higher than the vulcanization temperature is selected as the material of the core body 40, taking into consideration the vulcanization temperature set in the manufacture of the elastic crawler 30. From the viewpoint of ensuring the rigidity and abrasion resistance of the guide protrusions described below, it is preferable that the core body 40 is made of metal.

The core body 40 has a base portion 46 extending in the width direction and a pair of upright portions 48 extending inward from the ends of the base portion 46. Each upright portion 48 has a plate portion 50 and a protrusion portion 52 protruding outward in the width direction from the plate portion 50.

In FIG. 3, the double-headed arrow WC indicates the maximum width of the core 40. The core 40 shows its maximum width WC at the protrusion 52. The protrusion 52 is located between the top 54 and the bottom 56 of the core 10. The width of the core 40 is narrow at the top 54 and the bottom 56, and wide at the protrusion 52. In FIG. 3, the symbol PC indicates the position where the core 40 shows its maximum width. The maximum width position PC is also the top of the protrusion 52. The position where the core 40 shows its maximum width is located between the top 54 and the bottom 56 of the core.

The elastic crawler 30 has multiple core bodies 40. These core bodies 40 are arranged at intervals in the circumferential direction.

The tension body 42 extends in the circumferential direction. The tension body 42 is in the form of an endless strip. The tension body 42 is located outside the core body 40. Although not shown, the tension body 42 includes a steel cord. In the tension body 42, the steel cord extends substantially in the circumferential direction. "Substantially in the circumferential direction" means that the angle that the steel cord makes with the circumferential direction is 5° or less.

The reinforcing layer 44 extends in the circumferential direction. The reinforcing layer 44 is in the form of an endless strip. The reinforcing layer 44 is located outside the tension member 42. The reinforcing layer 44 includes at least one ply 58. The reinforcing layer 44 shown in FIG. 3 is made up of two plies 58. Although not shown, each ply 58 includes a number of parallel steel cords. These steel cords are inclined with respect to the circumferential direction. In this elastic crawler 30, the angle that the steel cords included in the plies 58 make with respect to the circumferential direction is preferably 45° or more, more preferably 50° or more, and even more preferably 55° or more. This angle is preferably 75° or less, more preferably 70° or less, and even more preferably 65° or less. From the viewpoint of ensuring the rigidity of the reinforcing layer 44, it is preferable that the inclination direction of the steel cords included in another ply 58 laminated on one ply 58 is opposite to the inclination direction of the steel cords included in this one ply 58.

The elastic crawler 30 has the following shape elements: a crawler body 60, a lug 62, and a guide protrusion 64.

The crawler body 60 extends in the circumferential direction. The crawler body 60 is an endless belt. The crawler body 60 includes an elastic member 38, a tension body 42, and a reinforcing layer 44. In the crawler body 60, the tension body 42 and the reinforcing layer 44 are entirely covered with the elastic member 38.

The lugs 62 are made of elastic members 38. The lugs 62 protrude outward from the outer peripheral surface 66 of the crawler body 60. The lugs 62 are long in the width direction and short in the circumferential direction. The lugs 62 contribute to the traction of the traveling device 22.

This elastic crawler 30 has a large number of lugs 62. These lugs 62 are arranged at intervals in the circumferential direction. This elastic crawler 30 has two lug rows, each row consisting of a large number of lugs 62 arranged in the circumferential direction. The two lug rows are arranged side by side in the width direction, sandwiching the center line CL.

The guide protrusions 64 protrude inward from the inner circumferential surface 68 of the crawler body 60. As described above, the rollers 28 roll on the elastic crawler 30. The inner circumferential surface 68 of the crawler body 60 defines a roller passing surface 70 along which the rollers 28 roll. In this elastic crawler 30, the roller passing surface 70 is defined on the guide protrusion 64 side of the inner circumferential surface 68 that extends outward in the width direction from the guide protrusions 64. The guide protrusions 64 protrude from the roller passing surface 70 defined on the inner circumferential surface 68.

The guide projection 64 has a top surface 72 and four side surfaces 74 extending from the top surface 72 toward the crawler body 60. Of these side surfaces 74, the side surface 74 located on the outer side in the width direction is the outer side surface 76. The guide projection 64 has a pair of outer side surfaces 76 located on the outer side in the width direction. Of the two side surfaces 74 that bridge the left and right outer side surfaces 76, the side surface 74 located forward in the direction of movement of the guide projection 64 when the traveling device moves forward is the leading side surface 78, and the side surface 74 located rearward is the trailing side surface 80.

In FIG. 3, the symbol PR denotes the root of the guide protrusion 64. This root PR is represented by the position where the wheel passing surface 70 and the outer surface 76 intersect. In FIG. 3, the double-headed arrow WR denotes the maximum width of the guide protrusion 64. In this elastic crawler 30, the guide protrusion 64 shows its maximum width WR at its root PR.

As shown in FIG. 3, the guide protrusion 64 is configured so that the distance between the left and right outer surfaces 76 gradually decreases from the base PR toward the top surface 72. The outer surface 76 of the guide protrusion 6 includes a first outer surface 82 on the base PR side and a second outer surface 84 on the top surface 72 side. The symbol PB indicates the boundary between the first outer surface 82 and the second outer surface 84.

As shown in FIG. 3, the inclination angle of the second outer surface 84 with respect to the thickness direction of the elastic crawler 30 is greater than the inclination angle of the first outer surface 82 with respect to the thickness direction of the elastic crawler 30. In this elastic crawler 30, it is preferable that the inclination angle of the first outer surface 82 is set in the range of 5° to 10°, and the inclination angle of the second outer surface 84 is set in the range of 20° to 40°.

In this elastic crawler 30, the guide protrusion 64 includes a core body 40 and an elastic member 38. The guide protrusion 64 includes a core body 40, which is covered with the elastic member 38.

As described above, the core body 40 has a base portion 46 extending in the width direction and a pair of upright portions 48 extending inward from the ends of the base portion 46. In other words, the core body 40 has a shape in which the central portion in the width direction is recessed outward. As shown in FIG. 3, the guide protrusion 64 of this elastic crawler 30 can be provided with a groove 86 recessed outward from the top surface 72. This results in a pair of flange portions 88 arranged side by side in the width direction being formed on the guide protrusion 64. The guide protrusion 64 having a pair of flange portions 88 contributes to preventing the elastic crawler 30 from coming off the track.

The core body 40 increases the rigidity and wear resistance of the guide protrusion 64. Moreover, this elastic crawler 30 can be configured with a pair of flanges 88 arranged in parallel in the width direction on the guide protrusion 64, for example, as described above. This elastic crawler 30 can be attached to various types of running devices 22, such as running devices 22 that use Matagi wheels, running devices 22 that use middle flange wheels, and running devices 22 that use double flange wheels. This elastic crawler 30 can also be attached to running devices 22 that have a wheel-fall prevention guide, also known as a boat-shaped guide. This elastic crawler 30 can contribute to improving wheel-fall resistance.

As described above, the width of the core body 40 is narrow at the top 54 and bottom 56, and wide at the protrusion 52. Since the core body 40 is covered with the elastic member 38, a zone (hereinafter, the first core body reflection zone 90) having a shape that follows the shape of the core body 40 (specifically, the protrusion 52) is formed on the outer surface 76 of the guide protrusion 64. In this elastic crawler 30, the thickness of the elastic member 38 in the first core body reflection zone 90 is 0.5 mm or less. In this elastic crawler 30, the first core body reflection zone 90 is a zone of the outer surface 76 of the guide protrusion 64 where the thickness of the elastic member 38, represented by the distance from the outer surface 76 to the core body 40, is 0.5 mm or less. This first core body reflection zone 90 includes the position PC where the core body 40 shows the maximum width. A thickness of the elastic member 38 of 0.0 mm means that the core body 40 is exposed.

In this elastic crawler 30, the first core reflecting zone 90 may be entirely made up of an elastic member 38 (hereinafter, a thin skin of the elastic member 38) of 0.5 mm or less that covers the protrusion 52. In the first core reflecting zone 90, the protrusion 52 of the core 40 may be exposed. In this case, the entire first core reflecting zone 90 may be made up of the exposed protrusion 52. A part of the first core reflecting zone 90 may be made up of the exposed protrusion 52, and another part may be made up of the thin skin of the elastic member 38. From the viewpoint of preventing the elastic member 38 from turning over and improving wear resistance, it is preferable that the entire first core reflecting zone 90 is made up of the exposed protrusion 52, i.e., the exposed core 40.

In this elastic crawler 30, there is no particular restriction on the shape of the first core body reflecting zone 90. The shape of this first core body reflecting zone 90 may be a rectangle, a square, a circle, or an ellipse. The shape of the first core body reflecting zone 90 shown in FIG. 2 is a rectangle.

In this elastic crawler 30, the maximum width WC of the core body 40 is narrower than the maximum width WR of the guide protrusion 64. The outer surface 76 of the guide protrusion 64 does not have a shape that follows the shape of the core body 40 as a whole, as in conventional elastic crawlers, but rather has a shape that follows the shape of the core body 40 in part. In other words, the outer surface 76 of the guide protrusion 64 includes a first core body reflecting zone 90 that has a shape that follows the shape of the core body 40 in part. In this elastic crawler 30, the volume of the elastic member 38 located between the outer surface 76 and the core body 40 is larger than that of the conventional elastic crawler 2. Since the proportion of the core body 40 in the guide protrusion 64 is low, this elastic crawler 30 achieves weight reduction even though the guide protrusion 64 includes the core body 40. The light elastic crawler 30 contributes to improving the fuel efficiency of the traveling device 22.

The configuration of this guide protrusion 64 is based on the new knowledge gained by the inventor through detailed research into the wear conditions of guide protrusions in conventional elastic crawlers. This knowledge is based on the fact that wear occurs on parts of the side surfaces and grooves, and that if the zone where this wear occurs has a shape that matches the shape of the core body, wear can be prevented without impairing the function of the guide protrusion.

This elastic crawler 30 can be made lighter while ensuring the rigidity and wear resistance of the guide protrusions 6. As mentioned above, this elastic crawler 30 can contribute to improved resistance to wheel derailment. This elastic crawler 30 can be made lighter while ensuring the rigidity and wear resistance of the guide protrusions 64, and can contribute to improved resistance to wheel derailment.

As described above, in this elastic crawler 30, the maximum width WC of the core body 40 is narrower than the maximum width WR of the guide protrusions 64. From the viewpoint of weight reduction, the ratio (WC/WR) of the maximum width WC of the core body 40 to the maximum width WR of the guide protrusions 64 is preferably 98% or less, and more preferably 96% or less. From the viewpoint of ensuring rigidity and wear resistance, this ratio (WC/WR) is preferably 90% or more, and more preferably 92% or more.

In this elastic crawler 30, the ratio of the area of the first core body reflecting zone 90 to the area of the outer surface 76 is preferably 10% or less. This further reduces the proportion of the core body 40 in the guide protrusion 64. This elastic crawler 30 can be further lightened. This elastic crawler 30 can contribute to improving the fuel efficiency performance of the traveling device 22. From this perspective, this ratio is more preferably 5% or less. From the perspective of ensuring the rigidity and wear resistance of the guide protrusion 64, this ratio is preferably 1% or more, and more preferably 3% or more.

The area of the outer surface 76 of the guide projection 64 is obtained based on the contour of the outer surface 76. In this elastic crawler 30, the contour of the outer surface 76 is represented by the boundary between the top surface 72 and the outer surface 76, the boundary between the leading side surface 78 and the outer surface 76, the boundary between the wheel passing surface 70 and the outer surface 76 (i.e., the root PR), and the boundary between the trailing side surface 80 and the outer surface 76. When each boundary is rounded, the contour of the outer surface 76 is specified by the intersection line between the top surface 72 and the outer surface 76, the intersection line between the leading side surface 78 and the outer surface 76, the intersection line between the wheel passing surface 70 and the outer surface 76, and the intersection line between the trailing side surface 80 and the outer surface 76. In this elastic crawler 30, the area of the outer surface 76 is represented by the sum of the area of the first outer surface 82 and the area of the second outer surface 84.

2, the double-headed arrow HT indicates the distance from the wheel passing surface 70 to the top surface 72 of the guide protrusion 64. This distance HT is the height of the guide protrusion 64. The symbol P1 indicates the position where the first core body reflecting zone 90 is closest to the wheel passing surface 70 (hereinafter, the bottom of the first core body reflecting zone 90). The double-headed arrow H1 indicates the distance from the wheel passing surface 70 to the bottom P1 of the first core body reflecting zone 90. This distance H1 is the height from the wheel passing surface 70 to the first core body reflecting zone 90. Note that in this elastic crawler 30, when the position of the wheel passing surface 70 changes in the thickness direction, the position of the root PR of the guide protrusion 64 is taken as the position of the wheel passing surface 70, and the distance is measured based on this wheel passing surface 70.

In this elastic crawler 30, the ratio (H1/HT) of the height H1 from the roller passing surface 70 to the first core reflecting zone 90 to the height HT of the guide protrusion 64 is preferably 20% or more, and preferably less than 50%. This makes it possible to achieve a good balance between the mass and rigidity of the guide protrusion 64 while suppressing wear on the outer surface 76. This elastic crawler 30 achieves weight reduction while ensuring the rigidity and wear resistance of the guide protrusion 64, and contributes to improving resistance to wheel slippage. From this perspective, this ratio (H1/HT) is more preferably 22% or more, and even more preferably 25% or more. This ratio (H1/HT) is more preferably 48% or less, and even more preferably 45% or less.

As described above, in this elastic crawler 30, the guide protrusion 64 can be provided with a groove 86 recessed outward from the top surface 72, thereby forming a pair of flanges 88 on the guide protrusion 64. The outer surface of the flanges 88 is the outer surface 76 of the guide protrusion 64, and the inner surface of the flanges 88 is the groove wall 92 of the groove 86. The groove bottom 94 of the groove 86 bridges the left and right groove walls 92.

Figure 4 shows a cross section of the elastic crawler 30 taken along line IV-IV in Figure 3. In Figure 4, the left-right direction is the circumferential direction of the elastic crawler 30. The up-down direction is the thickness direction of the elastic crawler 30. In Figure 4, the upper side is the inside of the loop, and the lower side is the outside of the loop. The direction perpendicular to the paper surface is the width direction of the elastic crawler 30. The left side of the paper surface is the front side of the traveling device 22, and the right side is the rear side of the traveling device. Line IV-IV in Figure 3 is also the center line CL.

As described above, in this elastic crawler 30, the guide protrusion 64 includes the core body 40, and this core body 40 is covered with the elastic member 38. As with the outer surface 76, the groove wall 92 of the groove 86 provided in the guide protrusion 64 also has a zone (hereinafter, the second core body reflection zone 96) having a shape that follows the shape of the core body 40 (specifically, the plate portion 50 of the rising portion 48). In this elastic crawler 30, the thickness of the elastic member 38 in the second core body reflection zone 96 is 0.5 mm or less. In this elastic crawler 30, the zone of the groove wall 92 of the groove 86 provided in the guide protrusion 64 where the thickness of the elastic member 38, represented by the distance from the groove wall 92 to the core body 40, is 0.5 mm or less, is the second core body reflection zone 96.

In this elastic crawler 30, the entire second core reflecting zone 96 may be constituted by a thin skin of the elastic member 38 covering the plate portion 50. In the second core reflecting zone 96, the plate portion 50 of the core 40 may be exposed. In this case, the entire second core reflecting zone 96 may be constituted by the exposed plate portion 50. A part of the second core reflecting zone 96 may be constituted by the exposed plate portion 50, and another part may be constituted by the thin skin of the elastic member 38. From the viewpoint of preventing the elastic member 38 from turning over and improving wear resistance, it is preferable that the entire second core reflecting zone 96 is constituted by the exposed plate portion 50, i.e., the exposed core 40.

In this elastic crawler 30, there is no particular restriction on the shape of the second core body reflecting zone 96. The shape of this second core body reflecting zone 96 may be rectangular, square, circular, or elliptical. The shape of the second core body reflecting zone 96 shown in FIG. 4 is rectangular.

In this elastic crawler 30, the groove wall 92 and the groove bottom 94 of the groove 86 do not have a shape that conforms to the shape of the core body 40 as a whole, as in a conventional elastic crawler in which a groove is engraved in the guide protrusion to form a pair of flanges, but rather have a shape that conforms to the shape of the core body 40 in part. In detail, the groove wall 92 of the groove 86 includes a second core body reflection zone 96 that has a shape that conforms to the shape of the core body 40 in part. In this elastic crawler 30, the volume of the elastic member 38 located between the groove 86 and the core body 40 is larger than that of the conventional elastic crawler. Since the ratio of the core body 40 to the guide protrusion 64 is low, this elastic crawler 30 achieves weight reduction even though the guide protrusion 64 includes the core body 40. The light elastic crawler 30 contributes to improving the fuel efficiency of the traveling device 22. From this perspective, it is preferable that the guide projection 64 has a groove 86 recessed outward from the top surface 72, and that the groove wall 92 of the groove 86 includes a second core body reflection zone 96 having a shape that follows the shape of the core body 40.

In this elastic crawler 30, the ratio of the area of the second core body reflecting zone 96 to the area of the groove wall 92 is preferably 10% or less. This further reduces the proportion of the core body 40 in the guide protrusion 64. This elastic crawler 30 can be further lightened. This elastic crawler 30 can contribute to improving the fuel efficiency performance of the traveling device. From this perspective, this ratio is more preferably 5% or less. From the perspective of ensuring the rigidity and wear resistance of the guide protrusion 64, this ratio is preferably 1% or more, and more preferably 3% or more.

The area of the groove wall 92 is obtained based on the contour of the groove wall 92. In this elastic crawler 30, the contour of the groove wall 92 is represented by the boundary between the top surface 72 and the groove wall 92, the boundary between the leading side surface 78 and the groove wall 92, the boundary between the groove bottom 94 and the groove wall 92, and the boundary between the trailing side surface 80 and the groove wall 92. When each boundary is rounded, the contour of the groove wall 92 is specified by the intersection line between the top surface 72 and the groove wall 92, the intersection line between the leading side surface 78 and the groove wall 92, the intersection line between the groove bottom 94 and the groove wall 92, and the intersection line between the trailing side surface 80 and the groove wall 92.

In FIG. 4, the double-headed arrow HG represents the distance from the groove bottom 94 of the groove 86 to the top surface 72 of the guide protrusion 64. This distance HG is the depth of the groove 86. The symbol P2 represents the position where the second core reflecting zone 96 is closest to the groove bottom 94 (hereinafter, the bottom of the second core reflecting zone 96). The double-headed arrow H2 represents the distance from the groove bottom 94 of the groove 86 to the bottom P2 of the second core reflecting zone 96. This distance H2 is the height from the groove bottom 94 of the groove 86 to the second core reflecting zone 96.

In this elastic crawler 30, the ratio (H2/HG) of the height H2 from the groove bottom 94 of the groove 86 to the second core reflecting zone 96 to the depth HG of the groove 86 is preferably 60% or more, and preferably 90% or less. This makes it possible to achieve a good balance between the mass and rigidity of the guide protrusion 64 while suppressing wear on the groove wall 92. This elastic crawler 30 achieves weight reduction while ensuring the rigidity and wear resistance of the guide protrusion 64, and contributes to improving resistance to wheel slippage. From this perspective, this ratio (H2/HG) is more preferably 62% or more, and even more preferably 65% or more. This ratio (H2/HT) is more preferably 88% or less, and even more preferably 85% or less.

As shown in FIG. 3, in this elastic crawler 30, the bottom 56 of the core body 40 is closer to the tension member 42 than the roller passing surface 70. In other words, the bottom 56 of the core body 40 is located outside the roller passing surface 70, in other words, on the road surface side. Even if a lateral force acts on the guide protrusion 64 by the roller 28, the elastic crawler 30 as a whole receives the force. Concentration of strain on the base PR of the guide protrusion 64 is suppressed. In this elastic crawler 30, damage such as cracks is prevented from occurring in the base PR of the guide protrusion 64. In this elastic crawler 30, the action of the guide protrusion 64 is maintained for a long period of time. From this viewpoint, in this elastic crawler 30, it is preferable that the bottom 56 of the core body 40 is located outside the roller passing surface 70.

In FIG. 2, the double-headed arrow DC represents the distance from the wheel passing surface 70 to the bottom 56 of the core body 40. This distance DC is the embedding depth of the core body 40.

In this elastic crawler 30, from the viewpoint of preventing damage to the base PR of the guide protrusion 64, the ratio (DC/HT) of the embedment depth DC of the core body 40 to the height HT of the guide protrusion 64 is preferably 8% or more, and more preferably 10% or more. From the viewpoint of reducing the weight of the elastic crawler 30 while ensuring the rigidity and wear resistance of the guide protrusion 64, this ratio (DC/HT) is preferably 20% or less, and more preferably 15% or less.

As described above, the elastic crawler 30 includes a reinforcing layer 44, which is located on the outside of the tension body 42. In other words, the crawler body 60 of the elastic crawler 30 includes a reinforcing layer 44 on the outside of the tension body 42. The reinforcing layer 44 effectively compensates for the loss of rigidity of the elastic crawler 30 due to the use of a small core body 40. In this case, it is preferable that the crawler body 60 includes a reinforcing layer 44 on the outside of the tension body 42 in the elastic crawler 30. In this case, it is more preferable that the reinforcing layer 44 is composed of two plies 58, as shown in FIG. 3, from the viewpoint that the reinforcing layer 44 can effectively compensate for the loss of rigidity of the elastic crawler 30.

As shown in FIG. 3, at the groove bottom 94 of the groove 86, the core body 40 is sufficiently covered with the elastic member 38. In this elastic crawler 30, the elastic member 38 at the groove wall 92 of the groove 86 is thin, but at the groove bottom 94 of the groove 86 is quite thick. Since the proportion of the elastic member 38 in the guide protrusion 64 is high, this guide protrusion 64 contributes to reducing the weight of the elastic crawler 30. From this perspective, in this elastic crawler 30, when the groove 86 is carved into the guide protrusion 64 to form a pair of flanges 88, it is preferable that the guide protrusion 64 is configured so that the elastic member 38 at the groove wall 92 of the groove 86 is thin and the elastic member 38 at the groove bottom 94 of the groove 86 is thick, from the viewpoint of reducing the weight while ensuring rigidity and wear resistance.

In FIG. 4, the double-headed arrow TC represents the distance from the groove bottom 94 of the groove 86 to the base 46 of the core 40. This distance TC is the thickness of the elastic member 38 at the groove bottom 94 of the groove 86. The double-headed arrow DB represents the distance from the groove bottom 94 of the groove 86 to the bottom 56 of the core 40. This thickness TC and distance DB are measured along the center line CL.

In this elastic crawler 30, from the viewpoint of reducing the weight of the elastic crawler 30, the ratio (TC/DB) of the thickness TC of the elastic member 38 at the groove bottom 94 of the groove 86 to the distance DB from the groove bottom 94 of the groove 86 to the bottom 56 of the core body 40 is preferably 30% or more, and more preferably 40% or more. From the viewpoint of ensuring the rigidity of the guide protrusion 64, this ratio (TC/DB) is preferably 60% or less, and more preferably 50% or less.

As is clear from the above description, the present invention provides an elastic crawler 30 that can reduce weight while ensuring the rigidity and wear resistance of the guide protrusions 6.

The elastic crawler described above can be applied to various crawler-type running devices.

2, 30: Elastic crawler 4, 60: Crawler body 6, 64: Guide projection 8, 62: Lug 10, 40: Core body 12, 38: Elastic member 14, 76: Outer surface 22: Running device 24: Sprocket 28: Roller wheel 42: Tension member 44: Reinforcing layer 46: Base 48: Upright portion 50: Plate portion 52: Projection portion 54: Top of core body 40 56: Bottom of core body 40 70: Roller wheel passing surface 72: Top surface 86: Groove 88: Flange portion 90: First core body reflecting zone 92: Groove wall 96: Second core body reflecting zone

Claims (11)

An endless belt-shaped crawler body;
A plurality of guide protrusions protruding from a wheel passing surface formed on an inner circumferential surface of the crawler body;
Equipped with
The crawler body includes a tension member extending in a circumferential direction,
The guide projection includes a core body,
The tension member and the core body are covered with an elastic member,
The maximum width of the core body is narrower than the maximum width of the guide protrusion,
The guide protrusion has a pair of outer surfaces located outward in the width direction,
Each of the outer surfaces includes a first core body reflecting zone having a shape that conforms to the shape of the core body in a portion thereof;
The guide projection has a groove recessed outward from a top surface,
a groove wall of the groove includes a second core body reflecting zone having a shape along the shape of the core body in a part thereof;
The ratio of the area of the second core reflecting zone to the area of the groove wall is 10% or less.
Elastic crawler. The core is exposed in the first core reflecting zone.
The elastic crawler according to claim 1 . The ratio of the area of the first core reflecting zone to the area of the outer surface is 10% or less.
The elastic crawler according to claim 1 or 2. The ratio of the height from the wheel passing surface to the first core reflecting zone to the height of the guide protrusion is 20% or more and less than 50%.
The elastic crawler according to any one of claims 1 to 3. The core is exposed in the second core reflecting zone.
The elastic crawler according to any one of claims 1 to 4 . The ratio of the height from the bottom of the groove to the second core reflecting zone to the depth of the groove is 60% or more and 90% or less.
The elastic crawler according to any one of claims 1 to 5 . The bottom of the core body is located outside the wheel passing plane.
The elastic crawler according to any one of claims 1 to 6 . The crawler body includes a reinforcing layer on the outer side of the tension body,
The reinforcing layer extends in a circumferential direction.
The elastic crawler according to any one of claims 1 to 7 . The position at which the core body has the maximum width is located between the top and bottom of the core body.
The elastic crawler according to any one of claims 1 to 8 . The position where the core shows the maximum width is included in the first core reflection zone.
The elastic crawler according to any one of claims 1 to 9 . The core body is made of metal.
The elastic crawler according to any one of claims 1 to 10 .

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